February 10, 2014 flash crash
On February 10, 2014, the BTC-E bitcoin exchange rate dropped by over $500, crashing from $620 to $102 in seconds, and then rebounding within two minutes. The crash is the result of what appears to be a single person selling at least 6,000 bitcoins significantly below the market price. As the sale was made with apparently extreme loss, it has been suggested that it was an attempt to manipulate trading bots.